Means for reversing electric motors.



No. 761,876. PATENTED JUNE 7, 1904. G. M. CLARK.

MEANS FOR REVERSING ELECTRIC MOTORS.

- APPLICATION FILED DEC. 10, 1902 R0 MODEL. 3 SHEETSSHEE T 1 a N [Tm 3 m o A 7 .mw' F6 Q4 No. 761,876. PATENTED JUNE 7, 1904.

' 0. M. CLARK. MEANS FOR REVERSING ELECTRIC MOTORS.

APPLICATION FILED DEG. 10, 1902.

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No. 761,876. PATENTED JUNE 7, 1904.

' 0. M. CLARK. MEANS FOR RBVERSING ELECTRIC MOTORS.

APPLICATION FILED DEO.10, 1902.

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UNITED STATES 'Eatented June 7, 1904.

CHARLES M. CLARK, OF SOUTH ORANGE, NEWV JERSEY.

MEANS FOR REVERSING ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent N0. 761,876, dated June '7, 1904.

Application filed December 10, 1902. Serial No. 134,602. (No model.)

To all whom it may concern:

Be it known that I, GHARLEs' M. C ARK, a citizen of the United States, and a resident of South Orange,in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Means for Reversing Electric Motors, of which the following is a specification.

My invention relates to electric motors, and is more particularly intended for use with telphers, though it may be used in any form of electric propulsion.

It has for its object to automatically reverse the motor at predetermined points.

In the drawings forming part of this specification, Figure 1 represents diagrammatically my invention applied to a telpher. Fig. 2 represents the invention applied to a telpher which carries an electric hoisting device. Fig.

3 is a diagrammatic view representing means for preventing the automatic reversing of the motor when passing an insulation in the conductor. Fig.4 is a view in perspective, showing the switch and the ratchet connected thereto, together with the circuit through the motor.

Referring to Fig. 1, A represents the track on which the telpher runs, and B the current- C represents the telpher, and D the trolley-pole. In most cases where it is desired to automatically stop the telpher at a predetermined point I provide in the line a dead section E, having at each end an insulating-block F, so that when the trolley-pole of the telpher is on said dead section the circuit is broken and the telpher stops. G represents a reversing-switch of the well-known rotary pattern, in which successive parts of a revolution will reverse the motorthat is to say, if the switch is turned a part of a revolution the motor will go ahead and the subsequent part of a revolution in the same direction will reverse the motor, this action continuing. In Fig. 4: I have shown this switch with a diagram of the wiring connections. I represents the switch, which is mounted on a shaft E, the other end of the shaft carrying the ratchet K. This switch is provided with the contact-pieces f g, with which are adapted to engage the brushes it it. The circuit through the motor is established as follows: from the trolley D through wire Z, brush 70, through contact-piece f, brush 71., wire on to and through motor C, through wire at, brush 1', through contact piece 9, brush e', wire 0, and track A. It will be readily observed that the turning of the switch a quarter of a revolution will reverse the motor. I provide an arm H, having a ratchet I so arranged that, as shown in the drawings, when the lever is raised the tooth will travel over the ratchet-teeth K on the switch and when the lever is depressed the pawl of the ratchet will engage the teeth on the wheel and cause the switch to rotate. This lever is operated by a solenoid L, the core M of which is attached to the end of the ratchet-lever H.

Between the core and the top of the solenoid is a spring N, which bearing on the top of the core depresses it when the solenoid is not energized. Running from the trolley-pole is a wire 0, which passes around the solenoid and thence back to the return, which in this case is shown as the track A. It will be observed, therefore, that when the current is on the solenoid will be energized, the core will be raised against the force of the spring N, and the ratchet-lever will be raised, the pawl traveling over the ratchet-teeth. When, however, the circuit is broken, as in the position shown in Fig. 1, the solenoid will be deenergized and the spring pressing the core of the solenoid. downward will operate the ratchet-lever to move the switch part of a revolution. This movement reverses the motor. The starting back of the motor is accomplished in any desirable manner, as by a current through a bypass P, which is controlled by a switch Q.

In order to operate with this switch,

motor places the switch-operating device in the proper position to reverse the switch. The current is supplied to the trolley-wire from any source of supply through the main switch R and wire S. T represents the return or ground wire.

Fig. 2 represents the invention as applied to a telpher, which carries an electric hoisting device, said hoisting device receiving its current from a separate wire. In this case a reversing-switch is supplied for both the telphermotor and the hoisting-motor, that for the hoisting-motorbeing lettered C. In this case the track acts as the common return of the two motors. The current here is supplied through the main switch R as before, said switch being of ordinary construction and used to control the amount of current flowing. 1 provide also a separate switch R, adapted to make contact with the terminals of the wire S, running to the telpher-conductor, and the wire S, running to the hoistingmotor conductor. in the position shown in Fig. 2, therefore, the switch of the telphermotor has been reversed, as heretofore described. The hoisting-motor having not yet received any currentits switch is in the proper position for causing the motor to lower the load. The switch R being moved to make contact with the terminal of the wire S, the cur rent passes through the hoisting-motor and, as heretofore described in connection with the telpher-motor, passes through the wire 0 to and around the solenoid L and back to the return, thus bringing up the core of said solenoid and raising the lever. The hoistingmotor now operates to lower the load, and when the load has reached the desired position the switch R is moved to the left to break the circuit, upon which the hoisting-motor is stopped and the switch antomaticall y reversed. On making connection again with the terminal of the wire S the core of the solenoid L will be drawn up as before, and the motor will operate in the hoisting direction. When the circuit is again broken through S when the hoisting-motor has reached the limit of its upward movement, the motor will be automaticall y reversed and as the current is broken also stopped. It is then in readiness for this operation to be repeated. The next step of the operation is to move the switch to the terminal of the wire S, upon which, as heretofore described, the telpher-motor will be operated and the telpher travel backward to its original starting position. It will be noted that either motor maybe reversed at will and as many times as desired by simply making or breaking the circuit through it by means of the switch R and that when either motor is stopped, so that the other one may be thrown into operation, the switches are automatically set for the next movement.

In telpherage systems in going around curves or in any place where it is desirable to decrease the speed of the motor I accomplish it by insulating that particular section of the line from the main conductor and sending the currentsupply to said insulated portion through a resistance, as shown in the patent to Harding, No. 692,136, January 28, 1902.

It will be observed that with the invention just described the motor would reverse when the trolley-pole passed over the insulatingblock in the wire were not some means taken to prevent it. In Fig. 3 1 have illustrated means for preventing reversal of the motor at such points. E represents that portion of the line having reduced current. F represents the insulation-block, and P represents the wire havinga resistance P, through which the reduced current is fed to the section E. The block F is shown as of exaggerated size in order to illustrate the invention. At the bottom of the insulating-block I provide two pivoted levers m a, which are normally depressed by a spring 7). The lever a is in electrical connection with the wire B and the lever a in electrical connection with the wire E. Above the levers are placed stops or contact-pieces 0 a. Running from the wire B is a wire (Z, which connects successively with the stops 0 c. ith the motor traveling toward the right in Fig. 3 the trolley-wheel will pass from the wire B onto the lever (1 raising it until it is in contact with the piece 0. The current will therefore be maintained through the motor. XV hen the trolley-wheel has reached the end of the lever 64, it comes in contact with the lever n, which it raises into engagement with the contact c, and, as will be readily observed, the

current is now maintained through the motor by means of the wire (Z and the contact 0. Upon leaving the lever a the trolley-wheel is in contact with the wire E, and the lever 1/ dropping breaks contact at (1, and the motor will therefore move along the section l] at a reduced speed.

It will be seen from the above description that though in the normal condition of the device the insulating-block serves the purpose of preventing the main current from passing through the section IE it nevertheless prevents when the trolley is passing the breaking of the circuit through the motor and consequent throwing of the switch. it will also be observed that the device will operate with the motor traveling in either direction.

lVhat 1 claim, and desire to secure by Letters Patent, is

1. An electric motor having a reversingswitch, means operated by breaking the circuit through the motor for reversing said switch, and means operated by the renewal of the current to place the parts in position to again reverse the motor, substantially as described.

2. An electric motor having a reversingswitch, ratchet mechanism for operating the same, asolenoid for moving the ratchet in the trolley is in contact with the block, substaninoperative direction and a spring for moving tially as described.

the same in the operative direction when the In witness whereof I have hereunto set my solenoid is deenergizecl, substantially as dehand, in the city, county, and State of New 5 scribed. York, this 4th day of December, 1902.

3. An insulating-block for a telpherage sysw w x tem for normally preventing the passage of the (JHARLEb LLAIUK' main current from one section of the Wire to In presence of the other, said block having means to ma1n- E. M. HARMON, IO tam the current through the motor When the 1 JOHN J. RANAGAN. 

